a {
    text-decoration: none;
    color: black
}

#navigation-form {
    background-color: white;
    border-radius: 3px;
    margin: 0 auto;
    height: 60%;
    padding: 20px;
}

.category {
    background-color: #F0F0F0;
    border: 1px solid #CCC;
    border-radius: 3px;
    width: 100px;
    height: 100px;
    padding: 20px;
    text-align: center;
}

.category > img {
    margin-bottom: 20px;
}

#categories {
    float: left;
}

#history {
    float: right;
}

#categories table tr td {
    padding: 5px;
}

#history table tr th, #history table tr td {
    padding: 10px;
}

#history {
    width: 40%;
}

input[type = "submit"] {
    margin-left: 5px;
}

